Angle grinding tools are commonly used for grinding and sanding applications. Angle grinders include a rotary shaft such as a wheel spindle for driving a grinding wheel mounted thereon. The present disclosure describes an improved shroud for guarding the grinding wheel. The present disclosure also describes a hinge assembly used in the angle grinder shroud.
According to an aspect of the invention a hinge assembly for attaching a door member to a main structure is provided. The hinge assembly, in an embodiment, includes a first hinge member securely attached to one of the door member or the main structure; a second hinge member securely attached to the other of the door member or the main structure and rotatably engaging the first hinge member; and a cam/spring assembly configured to bias the door member into an open or a closed position with respect to the main structure.
In an embodiment, the cam/spring assembly includes a first cam surface defined by a surface of the first hinge member and a second cam surface defined by a surface of the second hinge member and correspondingly engaging the first cam surface. In an embodiment, the first and second cam surfaces cause the second hinge member to move axially with respect to the first hinge member as the door member is rotated with respect to the main structure.
In an embodiment, the cam/spring assembly includes a compression spring having two ends respectively engaging the first and the second hinge members. In an embodiment, the compression spring biases the first and second cam surfaces to engage one another in an open or closed position of the door member with respect to the main structure.
In an embodiment, the first cam surface included a recessed surface and the second cam surface includes a projected surface engaging the recessed surface in the open and closed position of the door member with respect to the main structure.
In an embodiment, the first hinge member engages a first end of the spring and includes a cylindrical portion disposed inside the spring and the second hinge member engages a second end of the spring and includes a channel formed around the spring. In an embodiment, the second hinge member includes two hinge pieces mated together to form the channel around the spring. In an embodiment, the two hinge pieces include alignment features for mating the two hinge pieces together. In an embodiment, the first hinge member includes a second cylindrical portion and the second hinge member includes a second channel formed around the second cylindrical portion, the second cylindrical portion and the second channel not engaging the spring.
According to another aspect of the invention, a hinge assembly for attaching a door member to a main structure is provided. In an embodiment, the hinge assembly includes a first hinge member securely attached to one of the door member or the main structure, the first hinge member defining a first cam surface; a second hinge member securely attached to the other of the door member or the main structure and rotatably engaging the first hinge member, the second hinge member defining a second cam surface corresponding to the first cam surface; and a compression spring having two ends respectively engaging the first and the second hinge members, wherein the compression spring biases the first and second cam surfaces to engage one another in an open or closed position of the door member with respect to the main structure.
In an embodiment, the cam surfaces cause the second hinge member to move axially with respect to the first hinge members as the door member is rotated with respect to the main structure.
In an embodiment, the first cam surface included a recessed surface and the second cam surface includes a projected surface engaging the recessed surface in the open and closed position of the door member with respect to the main structure.
In an embodiment, the first hinge member engages a first end of the spring and includes a cylindrical portion disposed inside the spring and the second hinge member engages a second end of the spring and includes a channel formed around the spring. In an embodiment, the second hinge member includes two hinge pieces mated together to form the channel around the spring.
According to another aspect of the invention, a shroud assembly for an angle grinder having a grinding disc is provided. In an embodiment, the shroud assembly is configured to enclose the grinding disc and includes a shroud body; a shroud door rotatably attached to the shroud body to expose a portion of the grinding disc; and a hinge assembly disposed between the shroud body and the shroud door. In an embodiment, the hinge assembly includes a first hinge member securely attached to the shroud body; a second hinge member securely attached to the shroud door and rotatably engaging the first hinge member; and a cam/spring assembly configured to bias the shroud door into an open or a closed position with respect to the shroud body.
In an embodiment, the cam/spring assembly includes a first cam surface defined by a surface of the first hinge member and a second cam surface defined by a surface of the second hinge member and correspondingly engaging the first cam surface. In an embodiment, the first and second cam surfaces cause the second hinge member to move axially with respect to the first hinge member as the shroud door is rotated with respect to the shroud body. In an embodiment, the cam/spring assembly includes a compression spring having two ends respectively engaging the first and the second hinge members. In an embodiment, the compression spring biases the first and second cam surfaces to engage one another in an open or closed position of the door member with respect to the main structure.